Gelatinated explosives of great energy and constant detonation speed



FIPY QQ Patented July 12, 1932 UNITED STATES Room PATENT OFFICE ALFRED STETTBACHER, F ZURICH, SWITZERLAND No Drawing. Application filed June 16, 1930, Serial No. 461,651, and in Switzerland January 21, 1930.

Explosive gelatine and the high-grade gelatine dynamites derived therefrom are nowa-days still considered to be most efiective technical explosives. However, all these com- 5 positions show a relatively great sensitiveness to shocks, due to the indispensable chief constituent, viz, nitroglycerine. Another disadvantage which has been pointed out again especially of late, is that their original shat- 0 tering power is greatly reduced already after a short period of storage, seeing that their original maximum detonation velocity of 7100 to 6000 m/sec. is reduced to 2000 to 1000 m/sec. already after one or two weeks. Consequently these nitroglycerine explosives often prove insuflicient, in spite of their high energy, when hard and tough resistances have to be overcome, and are of but slight effect when employed for blasting iron or rein- 9 force-d concrete, and for tunnel-work and the sinking of petroleum wells. On the other hand aromatic nitrocompoundswhich detonate constantly with their maximum detonation velocity, such as trinitrotoluol and tetranitromethylaniline, prove unsuitable when employed as technical explosives, because by themselves they do not develop sufficient energy and evolve poisonous gases, whereas mixed with oxysalts, such as for instance ni- 0 trate of ammonium, they have to be diluted to such an extent that the detonation velocity of the whole mixture is reduced again to an average amount of 4000 to 5000 m/sec.

Explosives possessing the energy of best gelatine dynamite and even of explosive gelatine (nit-rogelatine), but detonating with constant maximum velocity are, according to the present invention, obtainable by thoroughly incorporating mixtures consisting of pentaerythrite tetranitrate and liquid nitric acid esters of polyvalent aliphatic alcohols, which mixtures are known as penthrinites and may contain also collodion-cotton, with inorganic nitrates or perchlorates, or a mixture of both, in the proportion stoichiometrically necessary for complete combustion. Obviously all the powdery admixtures generally used with gelatinized dynamites, such as for instance wood-dust and vegetable dust or phlegmatizing admixtures, such as for in stance aromatic and aliphatic hydrocarbon, may also be made use of to modify in one sense or another the character of the explosive. The phenthrinite mixtures supplemented by oxysalts with a View to obtain perfect combustion constitute an unexpected novelty as compared with the widespread gelatinated dynamites. In explosive gelatine (nitrogelatine) and gelatinized dynamites the system nitroglycerine-collodion-cotton is necessarily exhausted in respect to oxidation, so that powdery admixtures and oxysalts represent therein diluting admixtures which prejudice the uniformity of detonation. In penthrinite mixtures, on the contrary, oxysalts constitute desirable admixtures inasmuch as they increase the detonating power of the chief organic constituent and bring about the development of its energy in the most eiiicient manner. According to calculation 72.53, or 81.18 parts by Weight of a not easily congealable penthrinite mixture composed of 80% pentaerythrite tetranitrate, nitroglycerine and 5% glycoldinitrate (dinitroglycol) are supplemented to perfect combustion by 27.47 parts by weight of ammonium nitrate or 18.19 parts by weight of ammonium perchlorate. In these mixtures, which are characterized as a chemical necessity, the plastic penthrinite-component predominates to such a degree that the detonation velocity of the whole is not only not attained by any gelatine dynamite, but, in particular, is retained during storage of any length. The said mixture, consisting of penthrinite and ammonium perchlorate, having a density of 1.8, attains the maximum of energy and detonation ve locity and is therefore superior to explosive gelatine (nitrogelatine). Moreover its sensibility to shocks is considerably slighter than that of the corresponding oxysalt-dynamites, as pure penthrinite explodes under the 5 kg. hammer only at 28 cm. whilst nitroglycerine explodes already with a hammer-blow of 5 cm. By adding paraflin, pure or mixed with saltpeter-salts, the sensibility to shocks can be still further reduced, without appreciably reducing the predominant properties of penthrinite.

In the following examples the compositions Eammple I Plastic penthrinite mixture:

Per cent Pentae-rythrite tetranitrate 90 to 4 Nitroglycerine to 4 Dinitroglycol 20 to 2 Nitrate or perchlorate of ammonium radicle Na, or K singly or mixed" 70 to 10 VVood-dust or vegetable dust 0 to 5 Paraflin 0to 5 Aromatic nitro-hydrocarbons 2 to 20 Example [I Gelatinized penthrinite mixture:

Per cent Pentaerythrite tetranitrate 90 to 4 Nitroglycerine 7 0 to 4 Dinitroglycol 20 to 2 Collodion-cotton 8 to 0.5 Nitrate or perchlorate of ammonium radicle, Na or K, singly or mixed in any desired manner and proportion 70 to 10 Wood-dust or vegetable dust Oto 5 Paraflin 0to 5 Aromatic nitro-hydrocarbons 2 to 20 What I claim is 1. A plastic explosive containing oxysalts, possessing great energy and high and constant detonation speed, which can easily be pressed, comprising plastic mixture consisting of 90 to 4% pentaerythrite tetranitrate, 70 to 4% nitroglycerine, and 20 to 2% dinitroglycol, mixed with substances selected from a group consisting of 70 to 10% of nitrate of ammonium and perchlorate of ammonium, sodium and potassium in suitable proportion.

2. A plastic explosive containing oxysalts, possessing great energy and high and constant detonation speed, which can easily be pressed, comprising plastic mixture consisting of 90 to 4% pentaerythrite tetranitrate, 70 to 4% nitroglycerine, and 20 to 2% dinitroglycol, mixed with substances selected from a group consisting of 70 to 10% of nitrate of ammonium and perchlorate of ammonium, sodium and potassium in suitable proportion, with the addition of 0 to 5% vegetable dust, 0 to 5% paraifin, and 2 to 20% aromatic nitro-hydrocarbons.

3. A gelatinized explosive containing oxysalts, which possesses great energy and high and constant detonation speed, comprising a plastic mixture consisting of 90 to 4% pentaerythrite tetranitrate, 70 to 4% nitroglycerine, and 20 to 2% dinitroglycol gelatinized w th 8 to 0.5% collodion-cotton, and mixed with substances selected from a group con sisting of 70 to 10% nitrate of ammonium, perchlorate of ammonium, sodium and potassum in suitable proportion.

4. A gelatinized explosive containing oxysalts, which possesses great energy and high and constant detonation speed, comprising a plastic mixture consisting of 90 to 4% pentaerythrite tetranitrate, 7 0 to 4% nitroglycerine, and 20 to 2% dinitroglycol gelatinized with 8 to 0.5 collodion-cotton, and mixed with substances selected from a group consisting of 70 to 10% nitrate of ammonium, perchlorate of ammonium, sodium and potassium in suitable proportion, with the addition of 0 to 5% vegetable dust, 0 to 5% paraffin and 2 to 20% aromatic nitro-hydrocarons.

5. A gelatinized plastic explosive of great energy and highest detonation speed which remains constant, comprising gelatine-dynamites mixed with 4 to 90% pentaerythrite tetranitrate.

In testimony whereof I have signed my name to this specification.

ALFRED STETTBACHER. 

